Sound recording composition



Patented June 11, 1946 SOUND RECORDING comosmon Horace r. Billings, Haddonfield, N assignor to. Radio Corporation of America, a corporation of Delaware No Drawing,

"2 Claims. (01. 106-37) 7 v 1 d This invention relates to acomposition' of matter and to the method of preparing the same, and

p more particularly to a composition of matter suitable for use as a sound recording material.

Compositions of montan wax and stearic acid in theform of metallic soaps of sodium and lead have constituted recording wax-like compositions for many years. The gel-forming nature of these soaps is well known,- and when the soap ratio of uncombined fatty acid is balanced, films of ap- '10 proximately 0.020" to 0.030" thick assume a lustrous surface suitable for use-in sound recording. Heretofore, the flowing quality of such compositions has been controlled by temperature adjustments, and this has been relied upon to obtain level surfaces of the composition. In some cases, it is desirable to flow the wax-like composition onto a suitable base, such as glass, metal or the like in the form of a very thin film which forms the recording surface. the film must be of uniform thickness and entirely level. The flow characteristics'of the prior art compositions are not such as to afford even flow for very thin films.

The primary object of my present invention is to provide an improved composition of matter suitable for use in sound recording and free from the aforementioned difficulty;

More particularly, it is an object of my present invention to provide an improved composition of matter as aforesaid which will fiow out uniformly and evenly even in very thin film layers.

'A further object of my present invention is to provide a, method of preparing the improved composition of my present invention. 30

those not highly skilled in the art of fiowing'wax. 40

In accordance with my present invention, I

In such cases, obviously,

Application October 29, 1943, Serial No. 508,250

. 2 combination, may vary between the propomons of 1 to 1.5 and 1 to 3.5. i In a typical formula,'the soap stock mixture may be compounded of .30

per cent montan wax (having an acid value of 80 to 32 milligrams of potassium hydroxide per gram of wax), '60 percent stearic acid, 2.5 per cent to 3 per cent sodium and 5.5 to 8.5 per cent v lead. These percentages are based on the finished stock which constitutes a metallic soap base.

and the stock may beprepared according to well known methods practiced in the art.

. To impart to thei soap stock the desired flow characteristics, I then incorporate into it a plasticizer consisting of a mixture of a suitable wax,

15 a mineral oilfand free stearic acid. The wax may comprise an animal wax, such as spermaceti,

or a wax such as that sold under the trade name "Ceranova wax, which is manufactured by the Avon Importing Company, New- York city, and consists of a vegetable wax of amorphous nature. I have found that a plasticizer made up in the following proportions gives excellent results:

Ceranova wax-approximately 18 per cent.-

' White mineral oil-approximately 57 per cent. Stearic acid (triple pressed)approximately 25 per cent.

The above materials forming the plasticizer are added preferably in a particular sequence. First,

the Ceranova, wax and the white mineral-oil are in the neighborhood of 140 C. After this maizture has'been well stirred, and while still maintaining the stock at about 140' (2., the static acid is added in melted form and the entire mixture is well stirred to produce a homogeneolm mixture. The finished composition may then be cast into forms in suitable. molds. and subsequently remelted for flowing in thin, uniform films onglass, metal, or other suitable surfaces. The amount of improved plastlciner according incorporate into a suitable metallic soap base a. plasticizer comprising a mixture of a wax, a, mineral oil, and free stearic acid. The wax may be either of vegetable or animal origin, as more fully base or soap stock constitutes between 8 per cent set forth hereinafter. Preferably, the soap stock to 10 per cent by weight otthe finishedcomposiis om made up, after which the wax and mineral tiom The sound m erial produced as oil are preferably first added thereto, the free a above dwcribed is much more glossy fl stearic acid being added as the last ingredient. flar prior art compositions and has far less temb/ I In practicing the present invention, the soap ency to fog after cooling in the form of a film. stock or base may be made up of sodium and lead Also, a reeud made of the composition eoca'ding oompolmded with a mixture of stearic acid, and montan'wex. The montan wax to stearic acid andwillresultinmorefeithful ratiomayvar'ybetweentheproportionsofltoreproductfonotthem'lginslsmmds. zsandltotflhesodiumandleadin-chemical mthoushlhaveshownanddescribedbntone w my present invention which is added to the f to myprel'mtinventi'onwillbefolmdtobeexform of my invention and one method or preparing the same, it will undoubtedly be obvious .to those skilled in the art that many changesin both are possible within the spirit of the'present invention. I therefore desire that my invention shall not be limited except insofar as is made necessary by the prior art and by the. spirit of the appended claims.

I claim as my invention:

1. A composition of matter suitable for use in 10 recording sound which comprises a base of a. metallic soap in which is incorporated a plasticizer comprising a mixture of a wax, a mineral r oil and tree atearic acid. said mixture containing terial which comprises preparing a base stock oi one or more metallic soaps, and thereafter adding 5 to said stock a plasticizer'adapted to enhance the flow characteristics of said stock in relatit'ely'thin films, said plasticizer comprising a mixture 01' a wax, a mineral oil and stearic acid, and said wax and mineral oil being added to said stock prior to adding the stearic acid thereto. r

- HORACE P. *BILLINGS; 

